‹ All demos
Password maker
Strong passwords or easy-to-type word phrases, with an honest “how long to guess” meter.
How it works
- 1Made with your browser’s secure random generator. Nothing is sent or saved.
- 2Strength is counted in bits: how many equally likely choices there were. Guess time assumes ten billion guesses a second.
- 3Seven random words and a number are about as strong as 10 random characters — and much easier to type on a phone.
More demos
All demosLiveDatabases · Built from scratch
QueryLite: a SQL database
A SQL database written from scratch — parser, B+ tree indexes, a query planner, joins and transactions — running live on 22,000 rows in your browser.
Try it
LiveDistributed systems · Built from scratch
Raft consensus, live
The algorithm that keeps etcd and Kubernetes consistent. Five servers elect a leader and replicate a log — crash them and split the network while it runs.
Try it
LiveReal-time · Built from scratch
Live collaborative editor
Real-time editing with no server. Three devices share a note — take one offline, edit everywhere, reconnect, and they merge. Open a second tab and it syncs live.
Try it